SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0705d46859ce4463aabf639abba3d5673372c917bd9e3f84ddbe9776b2c83c10' 
  AND token = 'otZKnvXkzV7Pu3JPjYkoZ8AkHUOP5Euq+1MNnDdygvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}